Quantum model simulation of complete S→S1 population transfer by means of intense laser pulses with opposite chirp

Abstract

The effects of short (0.5–2 ps) chirped laser pulses on the vibrational population transfer from the electronic ground state S0 to the excited state S1 are investigated via numerical simulations of the wave packet dynamics. It is demonstrated for a model system that both positively and negatively chirped laser pulses with high intensities can achieve almost complete population transfer to the vibrational ground or low excited states in the electronically excited state. The underlying mechanisms of the transfer are, however, different, i.e., suppression and compensation of intrapulse pump–dump processes for the negatively and positively chirped pulses, respectively. The process induced by the negatively chirped laser pulse is applied to design complete S0→S1 population transfer to the lowest vibrational states of the first electronically excited state of 9-(carbazolyl)-anthracene (C9A) which could not be observed by means of traditional, i.e., continuous wave or ns spectroscopy.